Attentional modulation in perception of visual motion events.

Identical visual targets moving across each other with equal and constant speed can be perceived either to bounce off or to stream through each other. This bistable motion perception has been studied mostly in the context of motion integration. Since the perception of most ambiguous motion is affected by attention, there is the possibility of attentional modulation occurring in this case as well. We investigated whether distraction of attention from the moving targets would alter the relative frequency of each percept. During the observation of the streaming/bouncing motion event in the peripheral visual field, visual attention was disrupted by an abrupt presentation of a visual distractor at various timings and locations (experiment 1; exogenous distraction of attention) or by the demand of an additional discrimination task (experiments 2 and 3; endogenous distraction of attention). Both types of distractions of attention increased the frequency of the bouncing percept and decreased that of the streaming percept. These results suggest that attention may facilitate the perception of object motion as continuing in the same direction as in the past.     

Attentional sensitization of unconscious visual processing: Top-down influences on masked priming

Classical theories of automaticity assume that automatic processes elicited by unconscious stimuli are autonomous and independent of higher-level cognitive influences. In contrast to these classical conceptions, we argue that automatic processing depends on attentional amplification of task-congruent processing pathways and propose an attentional sensitization model of unconscious visual processing: According to this model, unconscious visual processing is automatic in the sense that it is initiated without deliberate intention. However, unconscious visual processing is susceptible to attentional top-down control and is only elicited if the cognitive system is configured accordingly. In this article, we describe our attentional sensitization model and review recent evidence demonstrating attentional influences on subliminal priming, a prototypical example of an automatic process. We show that subliminal priming (a) depends on attentional resources, (b) is susceptible to stimulus expectations, (c) is influenced by action intentions, and (d) is modulated by task sets. These data suggest that attention enhances or attenuates unconscious visual processes in congruency with attentional task representations similar to conscious perception. We argue that seemingly paradoxical, hitherto unexplained findings regarding the automaticity of the underlying processes in many cognitive domains can be easily accommodated by our attentional sensitization model. We conclude this review with a discussion of future research questions regar-ding the nature of attentional control of unconscious visual processing.     

Matching cue size and task properties in exogenous attention

Exogenous attention is an involuntary, reflexive orienting response that results in enhanced processing at the attended location. The standard view is that this enhancement generalizes across visual properties of a stimulus. We test whether the size of an exogenous cue sets the attentional field and whether this leads to different effects on stimuli with different visual properties. In a dual task with a random-dot kinematogram (RDK) in each quadrant of the screen, participants discriminated the direction of moving dots in one RDK and localized one red dot. Precues were uninformative and consisted of either a large or a small luminance-change frame. The motion discrimination task showed attentional effects following both large and small exogenous cues. The red dot probe localization task showed attentional effects following a small cue, but not a large cue. Two additional experiments showed that the different effects on localization were not due to reduced spatial uncertainty or suppression of RDK dots in the surround. These results indicate that the effects of exogenous attention depend on the size of the cue and the properties of the task, suggesting the involvement of receptive fields with different sizes in different tasks. These attentional effects are likely to be driven by bottom-up mechanisms in early visual areas.     

Attention affects the stereoscopic depth aftereffect

'Preattentive' vision is typically considered to include several low-level processes, including the perception of depth from binocular disparity and motion parallax. However, doubt was cast on this model when it was shown that a secondary attentional task can modulate the motion aftereffect (Chaudhuri, 1990 Nature 344 60-62). Here we investigate whether attention can also affect the depth aftereffect (Blakemore and Julesz, 1971 Science 171 286-288). Subjects adapted to stationary or moving random-dot patterns segmented into depth planes while attention was manipulated with a secondary task (character processing at parametrically varied rates). We found that the duration of the depth aftereffect can be affected by attentional manipulations, and both its duration and that of the motion aftereffect varied with the difficulty of the secondary task. The results are discussed in the context of dynamic feedback models of vision, and support the penetrability of low-level sensory processes by attentional mechanisms.     

发展性阅读障碍的视觉空间注意加工能力

鉴于阅读起始于基础视觉加工阶段, 越来越多的研究者开始关注阅读障碍者的视觉空间注意加工能力。视觉空间注意是指个体对视觉刺激的空间位置的注意, 可通过线索提示、视觉搜索和视觉注意广度等视觉任务来考察。大量国内外研究发现, 发展性阅读障碍者在视觉空间注意任务下表现出行为和神经活动方面的异常。其中的神经机制问题不仅反映在与视觉空间注意有关的顶叶区域激活异常, 还存在于脑区间功能连接异常(如顶叶区域与字形加工区的功能连接)。未来研究还需利用横断和追踪研究探讨阅读障碍与视觉空间注意能力发展关系的内在机制, 以及探究语言特性对阅读障碍者视觉空间注意缺陷的可能调节作用。     

Seeing while acting: hand movements can modulate attentional capture by motion onset

The onset of new motion has been shown to be a very robust cause of attentional capture, generating a processing advantage for the location of motion onset regardless of the observer's concurrent goal. The present study, motivated by the common-coding account of action and perception, examined whether the effect of motion onset on visual attention can be modulated by the observer's mode of action. Specifically, the common-coding account predicts that preparing an action can render the features that are used in the action plan less available for visual processes. Consistent with this hypothesis, in Experiment 1 the magnitude of attentional capture caused by a single motion onset was reduced when this motion was similar to the observer's response (i.e., along the same axis). Similarly, in Experiment 2 the onset of a response-different motion gained a processing advantage over the response-similar motion onset when the two were presented simultaneously. Since both types of motion were present in every trial, the results of Experiment 2 suggest that response similarity affected visual-attentional processes rather than motor processes. Together, these results suggest that the processes of attentional prioritization caused by motion onset can be modulated by the observer's concurrent action.     

无关工作记忆表征的负性情绪信息能否捕获视觉注意?一项眼动研究

研究通过分析视觉搜索任务的首次注视点和行为反应时, 探讨无关工作记忆表征的负性情绪信息对视觉注意选择的影响。实验1发现在反映早期注意选择的首次注视点百分率指标上, 不管工作记忆表征的情绪效价如何, 均出现了显著的注意捕获效应; 实验2发现当采用中性情绪靶子刺激时, 首次注视点百分率指标上仍表现出了稳健的注意捕获效应; 在首次注视点持续时间指标上, 实验1和实验2均发现记忆匹配条件的干扰刺激显著小于控制条件的干扰刺激, 表现出注意的快速脱离; 而在行为反应时指标上, 早期的注意捕获效应消失(实验1), 甚至被反转为注意抑制效应(实验2)。这些结果表明在早期注意选择阶段, 记忆驱动的注意捕获效应不受工作记忆表征情绪效价的影响, 但认知控制会在早期注意捕获之后促使注意快速脱离记忆匹配的干扰刺激, 其作用效果受靶子刺激情绪效价的调节。     

Do the contents of visual working memory automatically influence attentional selection during visual search?

In many theories of cognition, researchers propose that working memory and perception operate interactively. For example, in previous studies researchers have suggested that sensory inputs matching the contents of working memory will have an automatic advantage in the competition for processing resources. The authors tested this hypothesis by requiring observers to perform a visual search task while concurrently maintaining object representations in visual working memory. The hypothesis that working memory activation produces a simple but uncontrollable bias signal leads to the prediction that items matching the contents of working memory will automatically capture attention. However, no evidence for automatic attentional capture was obtained; instead, the participants avoided attending to these items. Thus, the contents of working memory can be used in a flexible manner for facilitation or inhibition of processing.     

Spatial attention and audiovisual interactions in apparent motion

In this study, the authors combined the cross-modal dynamic capture task (involving the horizontal apparent movement of visual and auditory stimuli) with spatial cuing in the vertical dimension to investigate the role of spatial attention in cross-modal interactions during motion perception. Spatial attention was manipulated endogenously, either by means of a blocked design or by predictive peripheral cues, and exogenously by means of nonpredictive peripheral cues. The results of 3 experiments demonstrate a reduction in the magnitude of the cross-modal dynamic capture effect on cued trials compared with uncued trials. The introduction of neutral cues (Experiments 4 and 5) confirmed the existence of both attentional costs and benefits. This attention-related reduction in cross-modal dynamic capture was larger when a peripheral cue was used compared with when attention was oriented in a purely endogenous manner. In sum, the results suggest that spatial attention reduces illusory binding by facilitating the segregation of unimodal signals, thereby modulating audiovisual interactions in information processing. Thus, the effect of spatial attention occurs prior to or at the same time as cross-modal interactions involving motion information.     

Attentional capture by motion onsets is modulated by perceptual load

The onset of motion captures attention during visual search even if the motion is not task relevant, which suggests that motion onsets capture attention in a stimulus-driven manner. However, we have recently shown that stimulus-driven attentional capture by abruptly appearing objects is attenuated under conditions of high perceptual load. In the present study, we examined the influence of perceptual load on attentional capture by another type of dynamic stimulus: the onset of motion. Participants searched for a target letter through briefly presented low- and high-load displays. On each trial, two irrelevant flankers also appeared, one with a motion onset and one that was static. Flankers defined by a motion onset captured attention in the low-load but not in the high-load displays. This modulation of capture in high-load displays was not the result of overall lengthening of reaction times (RTs) in this condition, since search for a single low-contrast target lengthened RTs but did not influence capture. These results, together with those of previous studies, suggest that perceptual load can modulate attentional capture by dynamic stimuli.     

Orienting of attention

Bartlett viewed thinking as a high level skill exhibiting ballistic properties that he called its “point of no return”. This paper explores one aspect of cognition through the use of a simple model task in which human subjects are asked to commit attention to a position in visual space other than fixation. This instruction is executed by orienting a covert (attentional) mechanism that seems sufficiently time locked to external events that its trajectory can be traced across the visual field in terms of momentary changes in the efficiency of detecting stimuli. A comparison of results obtained with alert monkeys, brain injured and normal human subjects shows the relationship of this covert system to saccadic eye movements and to various brain systems controlling perception and motion. In accordance with Bartlett's insight, the possibility is explored that similar principles apply to orienting of attention toward sensory input and orienting to the semantic structures used in thinking.     

工作记忆负荷、形状干扰对聋人与听力正常人注意捕获影响的眼动研究

通过记录和分析被试的行为和眼动指标,本研究试图探讨不同工作记忆负荷下,形状干扰对聋人与听力正常人不同视野位置上刺激信息捕获注意的异同。研究结果表明：（1）形状干扰刺激虽然没有影响被试视觉加工的认知绩效,但被试的眼动模式会由于工作记忆负荷的改变而改变,高工作记忆负荷时,有形状干扰的注视次数高于无形状干扰。（2）工作记忆负荷、视野位置影响被试视觉加工任务的完成,被试在不同视野位置的加工过程表现出不一致的眼动模式。（3）聋人视觉加工在高工作记忆负荷时存在一定的劣势,但其对不同视野位置的信息加工及形状干扰所产生的注意捕获效应与听力正常人一致。     

正常老化对视觉早期注意的影响——来自ERP的证据

选择性注意能够作用于视觉信息加工的不同阶段。各个注意阶段均受到老化过程的影响, 其中注意早期阶段的老化研究对于理解认知老化的发生机制有重要意义。本文系统地梳理了刺激前的注意预期阶段以及刺激后200 ms内的早期感知注意阶段的正常老年人和青年人ERP比较研究, 以探讨正常老化对视觉早期注意的影响。现有证据表明, 相对于青年人, 正常老年人：(1)多个早期ERP注意效应(包括注意预期ADAN, 早期空间注意N1, 以及特征注意SP和SN)在潜伏期上都存在显著延迟; (2)在振幅上, 不同ERP注意效应的老化表现存在差异：某些ERP成分(包括注意预期EDAN, 以及早期空间注意P1)的注意效应没有明显减弱, 而某些ERP成分(包括注意预期alpha, 早期空间注意N1, 以及特征注意SN)的注意效应受到老化调控; (3)一些注意效应(包括特征注意SP成分, 以及客体注意P1和N1成分)的目标增强机制保留, 而干扰抑制机制缺损。目前已有研究在老化对注意效应振幅的调控上还存在不一致, 这可能与研究的信噪比、任务难度、注意机制分离以及老年人的个体差异有关。未来研究应考虑这些因素以更好地探究正常老化对视觉早期注意的影响。     

Attention and perception: An information-integration perspective

Attentional effects in perceptual processing are analyzed within a framework of a fuzzy logical model of perception. The recognition of a pattern is conceptualized as involving three stages of processing: featural evaluation, integration of features, and pattern classification. The model predicts no loss of resolution when multiple sources of information are integrated to recognize a perceptual event. This model is contrasted with a single-channel model in which only one source of information can be recognized at a time. The task involves a relatively novel situation of speech perception by ear and eye. No attentional decrement is observed when observers process both auditory and visual speech specifying a single speech event. This result contrasts with previous studies showing a loss when attention has to be divided between different events along auditory and visual modalities. The different results are interpreted in terms of the number of events that have to be processed. Processing two different modalities leads to an attentional decrement when the two inputs specify different events whereas no attentional decrement occurs when these inputs are integrated to recognize a single event. A distinction is made between detection that requires only the evaluation of a single source of information and recognition that requires the evaluation and integration of multiple sources of information. The current framework is also used to discuss previous empirical and theoretical work and the issue of early versus late selection.     

EPS Mid-Career Award 2004: brain mechanisms of attention

There are many varieties of "attention", to some extent separate yet working together to produce coherent perception, thought, and behaviour. Using data from human behaviour, functional neuroimaging, and single-cell recording in the behaving monkey, I consider different levels of attention and their basis in physiological mechanisms of biased competition. Beginning with visual attention, I suggest that processing is competitive in many brain systems that code visual input. Competition is biased towards stimuli that match task requirements and is integrated between systems coding different object properties. The result is flexible, object-based attentional selection. In the second part of the paper, I describe recent experiments on attentional competition within and between sensory modalities. Though competition is often modality specific, more global levels of interference are also easy to demonstrate. In the third part of the paper, I move to frontoparietal cortex and to a pattern of similar brain regions recruited by many different cognitive demands. This multiple-demand (MD) pattern, I suggest, reflects neurons with highly flexible response properties, adapting to represent the information and events of many different tasks. Biased competition in MD regions may play a central role in broad attentional capacity limits and attentional focusing. More generally, I suggest that biased competition is characteristic of many different cognitive domains and brain systems. Coherent "attention" develops as different systems converge to work on related cognitive content.     

生物运动及其在社会认知障碍研究中的应用

人类对生物运动具有较强的视觉敏感性,即使在视觉线索有限的情况下,仍能提取其中的社会性信息。本研究系统梳理了当前生物运动视知觉实验研究涉及的各类社会性信息,并归纳分析社会认知缺陷与生物运动视知觉加工之间的内在联系,以期促进对生物运动视知觉加工心理机制问题的深入探讨     

时间任务需求对无关情绪面孔注意捕获的影响

注意捕获是指与任务无关的刺激能够不自觉地吸引注意的现象。实验一采用视觉搜索任务,考察与主任务无关的情绪面孔的注意捕获水平及其机制,实验二进一步探究时间任务需求对无关情绪面孔注意捕获的影响。结果发现:与其他情绪面孔相比,愤怒的情绪面孔捕获了更多的注意,且受到整体情绪加工的影响;时间任务需求影响了目标刺激的注意选择,但愤怒优势效应不受到时间任务需求的影响,因此可能是一种较为自动化的加工过程。     

Dividing attention between auditory and visual perception

To what extent is simultaneous visual and auditory perception subject to capacity limitations and attentional control? Two experiments addressed this question by asking observers to recognize test tones and test letters under selective and divided attention. In Experiment 1, both stimuli occurred on each trial, but subjects were cued in advance to process just one or both of the stimuli. In Experiment 2, subjects processed one stimulus and then the other or processed both stimuli simultaneously. Processing time was controlled using a backward recognition masking task. A significant, but small, attention effect was found in both experiments. The present positive results weaken the interpretation that previous attentional effects were due to the particular duration judgment task that was employed. The answer to the question addressed by the experiments appears to be that the degree of capacity limitations and attentional control during visual and auditory perception is small but significant.     

视觉与言语工作记忆表征对视觉注意的引导

通过三个实验,探讨不同时间进程下视觉和言语工作记忆表征对视觉注意的引导。实验1采用注意引导与注意探测任务同时呈现的范式,探讨不同记忆项与注意项时间间隔(SOA)条件下言语工作记忆表征对视觉注意的引导。结果发现,当SOA较短时言语工作记忆表征对视觉注意有引导效应,而SOA较长时未观察到引导效应;实验2、3采用注意引导任务与注意探测任务分离范式,分别探讨在不同SOA条件下言语和视觉工作记忆表征对视觉注意的引导。结果发现,不同SOA条件下言语和视觉工作记忆表征均能引导视觉注意。研究表明,不同实验范式对言语工作记忆表征对视觉注意的引导有明显影响,视觉比言语工作记忆表征能在更广泛条件下引导视觉注意。     

Investigating the role of exogenous cueing on selection history formation

An abundance of recent empirical data suggest that repeatedly allocating visual attention to task-relevant and/or reward-predicting features in the visual world engenders an attentional bias for these frequently attended stimuli, even when they become task irrelevant and no longer predict reward. In short, attentional selection in the past hinders voluntary control of attention in the present. But do such enduring attentional biases rely on a history of voluntary, goal-directed attentional selection, or can they be generated through involuntary, effortless attentional allocation? An abrupt visual onset triggers such a reflexive allocation of covert spatial attention to its location in the visual field, automatically modulating numerous aspects of visual perception. In this Registered Report, we asked whether a selection history that has been reflexively and involuntarily derived (i.e., through abrupt-onset cueing) also interferes with goal-directed attentional control, even in the complete absence of exogenous cues. To build spatially distinct histories of exogenous selection, we presented abrupt-onset cues twice as often at one of two task locations, and as expected, these cues reflexively modulated visual processing: task accuracy increased, and response times (RTs) decreased, when the cue appeared near the target’s location, relative to that of the distractor. Upon removal of these cues, however, we found no evidence that exogenous selection history modulated task performance: task accuracy and RTs at the previously most-cued and previously least-cued sides were statistically indistinguishable. Thus, unlike voluntarily directed attention, involuntary attentional allocation may not be sufficient to engender historically contingent selection biases.